A current-controlled flash sintering processing leading to dense and fine-grained typical multi-element ZnO varistor ceramics
| Autor: | Zhiyuan Liu, Guorong Chen, Haibo She, Muwen Cheng, Juan Liu, Dong Xu, Jingrong Xu, Bin Tang, Jingpeng Niu |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Mechanical Engineering Metals and Alloys Sintering 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Grain size 0104 chemical sciences Threshold voltage Mechanics of Materials Flash (manufacturing) Electric field Materials Chemistry Relative density Dielectric loss Composite material 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds. 876:160124 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2021.160124 |
| Popis: | Comparing to conventional sintering, the densification, microstructure and electric properties of typical multi-element ZnO-Bi2O3-based varistor ceramics on different constant furnace temperatures (850–1000 °C) were studied at electric field of 250 V/cm by flash sintering. The flash-sintered specimens of near full densification could be obtained within 35 s, which had finer grain size and more homogenous microstructure. The effect of different limited current on densification was investigated in flash sintering process. The results showed the relative densities of specimens from 89.9% to 92.0%, 95.5% while limited current increased from 1.0 A to 1.5 A, 2.0 A. The 950 °C flash-sintered specimen with the relative density of 98.0% had the highest threshold voltage of 656 V/mm with the nonlinear coefficient of 41.9. The dielectric loss of flash-sintered specimens had the value lower than 0.2. Thus, typical multi-element ZnO varistor ceramics could show uniform microstructure and excellent electric properties by constant furnace temperature flash sintering. |
| Databáze: | OpenAIRE |
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